title: Graphene quantum point contact transistor for DNA sensing.
abstract: By using the nonequilibrium Green's function technique, we show that the shape of the edge, the carrier concentration, and the position and size of a nanopore in graphene nanoribbons can strongly affect its electronic conductance as well as its sensitivity to external charges. This technique, combined with a self-consistent Poisson-Boltzmann formalism to account for ion charge screening in solution, is able to detect the rotational and positional conformation of a DNA strand inside the nanopore. In particular, we show that a graphene membrane with quantum point contact geometry exhibits greater electrical sensitivity than a uniform armchair geometry provided that the carrier concentration is tuned to enhance charge detection. We propose a membrane design that contains an electrical gate in a configuration similar to a field-effect transistor for a graphene-based DNA sensing device.
authors.affiliation: Departments of Physics and Electrical and Computer Engineering, and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801.
authors.forename: Anuj
authors.initials: A
authors.lastname: Girdhar
authors.forename: Chaitanya
authors.initials: C
authors.lastname: Sathe
authors.forename: Klaus
authors.initials: K
authors.lastname: Schulten
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Leburton
mesh_terms: D004247:DNA / Q000032:analysis*; D006108:Graphite / Q000737:chemistry*; D008567:Membranes, Artificial; D016062:Porosity; D045663:Quantum Dots; D014173:Transistors, Electronic
chemical_list: D008567:Membranes, Artificial; D006108:Graphite; D004247:DNA
keywords: bio-molecule; simulation; solid-state membrane; transport